In-place jogging and climbing devices are known in the exercising arts, such as in U.S. Pat. No. 4,279,415, S. Katz, Jul. 21, 1981 for Exercising Device. Thus, two independent side-by-side coil spring biased treadles are manipulated in a jogging or climbing action by coordination of the feet of the user to compress both work absorbing springs and surrounding plastic foam. The foam and springs, however, are limited in height and length of operation and do not produce a consistent work load throughout a work stroke, so that realistic and comfortable foot action is afforded. Furthermore, pivoted, slanted treadles require ankle bending and makes the most force bear upon the toes so that the body action is not ideal, particularly for jogging motion.
A variation of this device is shown in U.S. Pat. No. 4,204,675, G. McGinnis, May 27, 1980 for Air Chamber Leg Exercising Device, which uses both compressible "breathing" elastic air chamber bags and spring loaded treadles for establishing a work load, in which the exit resistance of exhausted air from the bags is controlled by a manually operable spring bias loading for an exhaust valve to establish a partly variable work load. The treadle is connected to the air bag wall to force it to suck in air from a flap valve as it is raised. Treadle hinge springs, valves and bags are critical in control and subject to overload by exerciser's weight, etc. and have limited reliability and life. Furthermore, the breathing controls take a finite time to operate in filling the bags for a power stroke, and thus limit the speeds and interfere with natural rhythm in exercising.
Bellows type air compression chambers are disclosed in U.S. Pat. No. 4,635,931, G. Brannstam, Jan. 13, 1987 for Apparatus for Arm and Leg Exercise. This device is used by persons lying in a bed. The air in the bellows is forced in and out by exercise. Air intake and exhaust valves require the foot to be attached to the bellows, which in turn is attached to the bed, and adjustable valves resist the intake and exhaust of air to regulate the respective work loads of pushing and pulling. This operating principle is not adaptable to jogging or climbing exercise where the exercising force for each leg is provided on a downward compression stroke only.
A bladder type bag eliminates treadles in U.S. Pat. No. 4,405,129, J. Stuckey, Sep. 20, 1983 for Therapeutic Exercise Device. The bladder can be blown up to a desired pressure above atmospheric, and foot (or other body part) pressure upon two bladder compartments transfers air reciprocally from one to the other over a restricted passageway that determines in part the work load, as modified by the pressure within the bladder. This bladder construction provides a very limited work stroke length, and does not provide a sense of balance that comes with a rigid treadle platform.
One primary deficiency in the art is the inability to provide long enough stroke distances for requiring leg action and bending of the knees in jogging and climbing exercises, and stroke adjustments for adaption to various user's preferences or for simulating the distance between stair steps.
Another criticism of the prior art exercising devices is the dependency upon springs. Not only are springs costly, but they have limited life, are subject to change and stress during the course of use, are not adaptable to long or variable strokes, and afford a very limited range of work load variation.
Exercise devices should also provide an optional versatility of body building exercises. The prior art jogging-climbing devices of simple and inexpensive construction, for example, do not afford arm and shoulder exercise, as might be afforded when jogging by means of swinging weights synchronously with foot action. Further, exercising from standing, sitting and lying positions is rarely feasible in prior art devices of the class herein proposed.
The treadle operated exerciser devices of the prior art also have not been comfortable in operation to give a sense of balance when riding, walking, climbing or jogging in place on the treadles. Prior art construction of the treadles, particularly with slanted and spring biased treadle structure, tends to fatigue or over exercise ankle joints.
Thus it is a primary objective of this invention to provide improved exercising apparatus that overcomes the aforesaid prior art deficiencies. Objectives include the provision of inexpensive, reliable and versatile exercising devices for in-place riding, jogging or stair climbing exercises. Other objects, features and advantages of the invention will be found throughout the following description, claims and accompanying drawings.